1. When pruning, it is advisable to disinfect pruning shears when moving from one plant to the next so as to prevent the spread of pathogens – bacteria, fungi, and viruses – that cause disease. Common rubbing alcohol or a bathroom disinfectant spray are suitable for this task. Ornamental shrubs in the rose family – photinia, toyon, pyracantha, and ornamental pear – are especially susceptible to a bacterial disease known as fire blight, carried in plant sap, that causes shoot ends to appear as though they have been torched. When pruning these plants, shears should be disinfected between one cut and the next. Before storing your pruning tools, disinfect them one more time, dry them, and then apply lubricating oil to screws and blades. After pruning roses or deciduous fruit trees, remove all leaves so that plants can enter dormancy, a necessary physiological condition to ensure maximum bloom in the spring.
2. Now is the time to winter prune roses. There are two approaches to winter pruning, one radical and the other conservative. The radical approach reduces all canes to less than two feet in height, while the conservative approach leaves canes at least four feet tall. Radical pruning results in a spring crop of roses that are large in size but relatively few in number, while more conservative pruning yields a bigger rose harvest, yet one whose flowers are of a reduced size. Regardless of how much you prune, the resulting plant should have a vase shape so that all new growth will receive maximum light and expanding shoots will not touch each other. For disease and pest resistance, plant shrub and floribunda roses, although their flowers are smaller and more mildly fragrant than those of hybrid teas. Floribundas are sometimes called landscape roses because of their suitability for hedging, their lush foliage and their compatibility, design-wise, with a wide spectrum of plants.
3. If you are wondering which California natives to plant, take a clue from those that are currently showing new growth, whether they are found on the hills around you or on the Channel Islands, which many of them call home. These are the ones to get into the ground now so that they have a whole year to acclimate before being called upon to send out new growth once again. Sturdy woody natives such as manzanita (Arctostphylos spp.) and Ceanothus are always recommended, but keep in mind perennial monkeyflowers (Mimulus spp.) and perennial lupines (Lupinus spp.) as well. You can also plant Australian and South African natives now since they grow under climatic conditions and in soil similar to our own. There is a plethora of Proteas, Grevilleas, picushions (Leucospermum) and conebushes (Leucadendron) from which to choose.
4. There is always the possibility of a hard frost or freeze that burns foliage and turns wood to mush. The foliage and bark of cold-sensitive tropical plants such as ficus trees may appear to be water-soaked following a freeze, and for good reason: The freezing and thawing of plant cells causes them to burst. Citrus fruit, many of which ripen during winter, may not look damaged on the outside, but their lack of firmness will give away the softened and inedible condition of their pulp. There is really nothing you can do to salvage cold-damaged plants other than to wait and see if they recover. I remember one severe freeze that killed back an 8-foot-tall umbrella tree (Schefflera actinophylla) almost down to the ground. A single bud at the base of the trunk remained viable, yet it managed to regrow into another 8-foot tree. Under no circumstances should the dead portions of any frost-damaged plant be pruned back until consistent warm weather returns in the spring. Pruning such a plant would expose still healthy cells to the cold and also stimulate new, tender growth even more susceptible to injury than the already damaged older growth.
5. Although it is a wise practice to conserve as much water as we can by collecting rainwater in barrels, for example, there is one place where water collects that can be deleterious to plant growth. I am talking about the dishes under container plants. Standing water is always an invitation to the growth of disease organisms that can rot plant roots. Succulents and cacti are especially susceptible to such diseases, especially in winter when they experience dormancy. That is also a reason that warm weather planting is recommended where succulents are concerned. Our instinct is to water any newly planted specimen but doing so in the case of succulents and cacti, during winter, is not recommended since standing water in cold soil could lead to their demise.
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